_561.java

package com.fishercoder.solutions;

/**
 * Created by fishercoder on 4/23/17.
 */

import java.util.Arrays;

/**
 * Array Partition I:
 *
 *
 * Given an array of 2n integers, your task is to group these integers into n pairs of integer,
 * say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of min(ai, bi) for all i from 1 to n as large as possible.

 Example 1:
 Input: [1,4,3,2]

 Output: 4
 Explanation: n is 2, and the maximum sum of pairs is 4.

 Note:
 n is a positive integer, which is in the range of [1, 10000].
 All the integers in the array will be in the range of [-10000, 10000].*/
public class _561 {

    public int arrayPairSum(int[] nums) {
        Arrays.sort(nums);
        int sum = 0;
        for (int i = 0; i < nums.length; i += 2) {
            sum += nums[i];
        }
        return sum;
    }

}